The present invention relates to projectiles and missiles and, more particularly, to positively roll-stabilized guided missiles, "smart bombs" or warhead including remote pilotless vehicles designed to reach and penetrate specific hardened targets.
For ease of presentation, the present invention is described herein in terms of a guided missile, it being understood that the present invention is of far broader applicability.
A typical guided missile is commonly made up of a number of sections, which are housed in, or connected to a generally cylindrical housing of varying radius in the longitudinal direction.
At the front of the missile is the guidance section which typically includes one or more sensors, such as a Forward Looking Infrared (FLIR) or video camera, and the various electronic systems which control the sensors, analyze and interpret the signals received by the sensors, and control the flight control system which positively determines the trajectory and the roll position of the missile. The guidance section may also include means for receiving signals from outside of the missile and may also include means for transmitting signals from the missile.
Behind the guidance section is the warhead which is typically a hollow cylindrically shaped casing, typically made of a high strength steel. The function of a penetration warhead is to penetrate a hardened target and place the explosive charge in the appropriate position, i.e., inside the target, at the moment of explosion, thereby maximizing the effect of the explosion on the target. Inside the hollow casing is placed the explosive and the rear end of the warhead lies the ignition fuse which is designed to be set off at the proper moment, typically, at some predetermined time after the warhead encounters the target. The warhead is typically made of three sections: (1) a front section, or nose, which is usually in the shape of an ogive or cone; (2) the main section which includes the explosive charge and is usually cylindrical; and (3) the aft section which seals the explosive charge within the casing and holds the fuse.
Behind the warhead typically lies the engine which provides thrust to the missile.
Housed in and connected to the housing at the rear of the missile, and in some cases also in other locations along the missile housing, is the flight control section, including fins and foils, which are used to adjust and stabilize the trajectory of the missile during its flight to the target and to prevent the missile from rolling during, flight.
For maximum penetration of the hardened target(et it is desirable to have the missile impact the target directly, i.e., at a 90.degree. to the target surface. In most cases, however, the angle of impact is different, sometimes significantly, from the optimal 90.degree..
For example, a significant fraction of hardened targets, such as command bunkers, and the like, are built into the ground and have an outer wall which is substantially horizontal. A typical guided missile would typically impact the outer wall at an angle which, in many cases, may be in the range of from about 45.degree. to about 65.degree., substantially different from the optimal angle of 90.degree.. The deviation of the impact from the perpendicular greatly reduces the penetration depth of the warhead into the target and significantly decreases the effectiveness of the explosion.
There is thus a widely recognized need for, and it would be highly advantageous to have, a warhead which is configured so as to improve its penetration when impacting the target at an angle which deviates from the perpendicular.